Working with Perranwell to proactively mitigate flood impacts across the community

Background

The Parish of Perranwell consists of approximately 750 properties, and it has faced multiple floods over the years, predominantly due to the river flowing through its centre. The community has experienced significant damage and losses as a result of these floods, affecting various establishments such as the village pub, garage, and numerous residential homes.

Perranwell's response to these challenges involves the formation of an Emergency Plan Working Group (EPWG), which is spearheaded by the local council. This group also includes dedicated local volunteers, all sharing a vested interest in ensuring the safety of the village. Recognising the need for proactive measures, the community is focused on implementing prevention strategies.

Challenge

The primary challenge faced by the Parish of Perranwell is the recurrent flooding that has led to substantial loss and damage. The impact extends to critical community infrastructure, including the village pub, garage, and residential properties. In response to these challenges, the community has established an EPWG to address the issue and has enlisted the assistance of specialists, such as Louisa Inch of Premier Water Solutions, to provide expert advice on developing an emergency plan. The emphasis of the plan is on conducting a risk survey and prioritising Property Flood Resilience (PFR) to mitigate the adverse effects of future flooding events.

Solution

Early warnings are an important component of the village's multi-peril emergency plan. Previsico, in partnership with Watertight International, worked with the EPWG, installing a level sensor in Perranwell Station to protect the local community from fluvial flooding.

The device replaces a legacy instrument that had stopped working and monitors water depth within Trewedna Water, an ordinary watercourse that runs through the village. The device is configured to generate alerts for the local community during periods of flood.

Impact

Over 1,000 residents and dozens of businesses are now benefitting from the installed device, with this only realised through the sound actions of the EPWG and Emergency Plan.

Since installation there have recently been multiple events where the sensor has sent out a critical warning to the EPWG, allowing time for emergency services to arrive on site and help prevent a serious flooding event in the village. The village will still be at risk of flooding, but these risks have been mitigated significantly by a forward-thinking community and council.

The sensor in action

During the late October to early November 2023 period, Storm Ciaran resulted in substantial rainfall in Cornwall, including Perranwell. The rise in water level was detected by Previsico's sensor situated at Perranwell Station, prompting an alert to be issued to the Emergency Plan Working Group (EPWG).

This early warning system plays a crucial role in the village's multi-peril emergency plan, enabling timely intervention to mitigate the potential adverse effects of flooding on the community.

At the beginning of 2024, Storm Henk resulted in substantial rainfall in Cornwall, including Perranwell. Perranwell's sensor alerted the Emergency Plan Working Group (EPWG). On two occasions the water levels rose above the pre-set threshold.

"We are very proud of our village which was damaged following a significant flood event. It was extremely stressful and costly, so we decided that we had to take action to reduce the risk. Our FLAG called in Previsico who worked with us to enhance our resilience with their Sensor Solutions to support our flood action plan."

Councillor Richard Holman